JPS621576A - Heat-sensitive transfer recording ink sheet - Google Patents

Abstract

PURPOSE:To prevent the occurrence of blocking in the case when an ink sheet is formed in a roll or a laminate, by forming a layer of specific polydimethyl siloxane. CONSTITUTION:A layer of polydimethyl siloxane expressed by a general formula (I) is formed on the side of an ink sheet whereon a quantity of heat is impressed. In the formula, (n) is 50-6,000. In order to form the layer of polydimethyl siloxane expressed by the general formula (I) on the ink sheet, the compound as it is, or the one diluted with an inactive solvent, is formed on the ink sheet. The desirable thickness of coating is 0.02-1mum, or preferably 0.05-0.5mum. Although the ink sheet whereon the layer of polydimethyl siloxane is formed is not limited particularly, an especially conspicuous effect is produced with respect to the one of a melt transfer type.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer recording ink sheet, and more particularly to an ink sheet forming a part of a recording medium used in a transfer type thermal recording device.

[Conventional technology]

In recent years, the spread and progress of information devices has been remarkable.In particular, as personal computers, office computers, and word processors have become popular, the number of printers installed in these devices has rapidly increased.

Against this background, thermal transfer printers, which are small, lightweight, inexpensive, and highly reliable, perform recording by applying a predetermined amount of heat to an ink sheet and transferring the ink to recording paper.

There are several methods for this thermal transfer, and a typical one uses a thermal head to apply heat, a wax layer containing pigment is provided on the sheet, and the heat application part of the thermal head is melted and transferred to the transfer paper. There are methods such as a method in which a sublimable dye is contained in a binder and sublimation and diffusion transfer are performed by applying heat from a thermal head, and a heating method is a method in which electrical heating is applied via an ink sheet.

All of these require higher sensitivity, ie, high-speed printing, etc., and naturally a material with a relatively low melting point must be used as the ink layer. However, for convenience of installation in the printer, this ink sheet is made into a cartridge, and has no choice but to take the form of a roll or a stack of sheets (q
First, in this state, since a material with a relatively low melting point is used as the ink layer, so-called blocking occurs due to the rolling pressure or its own weight, resulting in migration and peeling of the ink layer, or integration due to side seepage, or the ink sheet ,
A disadvantage is that the ends of the ribbon may fall off.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention is to solve the above-mentioned drawbacks of conventional ink sheets, that is, the problems caused by so-called blocking that occur when the ink sheet is in the form of a roll or a stack of sheets. .

[Means for solving problems]

The above problem is that on the side of the ink sheet where the heat is applied,
The problem is solved by forming a layer of a specific polydimethylsiloxane, preferably with a thickness of 0.02-1 .mu.m. That is, the present invention relates to a thermal transfer recording ink sheet having the following general formula on the side to which heat is applied.

Originally, there is a backside treatment for this type of ink sheet to improve the drawbacks that occur when heat is applied. That is, this is a process that attempts to eliminate the sticking phenomenon caused by softening of the ink sheet base material by covering it with a heat-resistant rod material or by improving the slipperiness of the base material. Japanese Unexamined Patent Publication No. 55-
146790. JP-A-56-155794, JP-A-57
-129789, JP-A-58-171992, JP-A-5
8-187396, etc., and some use silicon-based compounds. However, these are all treatments for instantaneous phenomena during heat application and recording, and are treatments to improve the instantaneous softening or slipperiness of the base material that occurs when heat is applied. The thermal characteristics of the base material or the frictional properties of the base material have a large influence.

On the other hand, the prevention of blocking that the present invention attempts to solve involves the problem of peelability after a long period of time, and is essentially completely different from the above-mentioned conventional treatment that deals with instantaneous phenomena when heat is applied. It is completely unclear whether or not these different methods, which are effective in conventional processing, will be effective when used as they are for blocking prevention according to the present invention.

[Effect]

General formula used in the present invention A range of 50-4000 is preferably employed.

If n is less than 50 and the treated thickness is large, the material may ooze out at the edges during stacking.

In addition, if the diameter is 6000 or more, there may actually be restrictions in terms of materials. Specific examples of these include polydimethylsiloxane PSO40 (n=50) manufactured by Chisso@
, PS 041 (n = 80> , PS 043 (n
=370), PS 046(n -910), P
S 049 (n = 3500), PS 050 (n
= 5840), and 5H-200 silicone oil manufactured by Toshi Silicon ■, which satisfies the above conditions. These may be used alone or in combination of two or more.

In addition, in the present invention, other polymers or oligomer compounds can be used in combination, and examples of other polymers in this case include ethylene copolymers such as ethylene-vinyl acetate and ethylene-acrylic, polystyrene, and styrene. -butadiene copolymers, rubbers, cellulose derivatives, butyral, polyvinyl alcohol, polyamides, polycarbonates, polyvinyl chloride, epoxymelamine,
Examples include polyester, polyether polyurethane, and the above-mentioned oligomeric compounds, which are usually 0.5
Used in combination at a rate of ~8Qfflfft%.

Furthermore, the present invention does not preclude the use of inorganic additives. The inorganic additive at this time is used, for example, to avoid a decrease in thermal conductivity, or in the case of electrical heating, to not impede the conductivity. Preferred specific examples include metal powders such as silver, copper, iron, etc. Examples include powders of metal oxides such as aluminum, such as alumina, white titanium, glass, etc., powders of inorganic salts such as calcium carbonate, sodium sulfate, clays, etc., and the amount used is usually a proportion of polydimethylsiloxane and other additives. It is about 10-80 parts by weight based on the total amount.

When forming a layer of polydimethylsiloxane represented by the above general formula on the side of the ink sheet to which heat is applied, the compound is applied as it is or diluted with an appropriate inert solvent and applied to a predetermined location on the ink sheet. It is formed by a means such as a coating means.

In this case, from the viewpoint of workability, the inert solvent should have a boiling point of 50-
A temperature of 150°C is preferable, and specific examples include toluene, xylene, hexane, ethyl acetate, butyl acetate,
Examples include acetone, methyl ethyl ketone, and methyl isobutyl ketone. The order in which the polydimersiloxane layer of the present invention is formed may be after the ink layer is provided on the base material, or the polydimethylsiloxane layer may be provided on the base material in advance, and then the ink layer may be provided. The coating thickness is 0.
02-1μ, preferably in the range of 0.05-0.57A; below 0.027μ, a uniform effect cannot be expected;
Moreover, if it is 1 JP or more, the sensitivity of the ink sheet decreases, which is not desirable.

The ink sheet on which the polydimercyl O xane layer of the present invention is formed is not particularly limited, and any of the various types that have been conventionally used can be used. Among these, the effects of the present invention are particularly noticeable in the melt-transfer type. These ink sheets are not particularly limited as mentioned above, but to explain the melt transfer type that is preferably used in the present invention as an example, a polyester film base with a thickness of about 2-12/P is used. On the material, an ink layer prepared from paraffin wax or ester wax having a melting point of about 60-100°C and a coloring material, along with a filler as a softener and a thermal conductivity improver if necessary, is applied to a thickness of about 2-207L4. I can give an example of what was set up.

A wide variety of coloring materials can be used, including pigments listed in Table 1 of the Dye Handbook (published by Maruzen Co., Ltd., 1970), pigments such as carbon black, direct dyes, and dispersions. Various dyes such as dyes, basic dyes, and acid dyes can be used.

'Particularly preferred are yellow coloring materials having a chlorphenylazo group, magenta coloring materials having a naphtholazo group, and cyan coloring materials having a phlocyanine channel.

As softeners, conventionally used ones can be used, such as ethylene-based copolymers such as ethylene-vinyl acetate and ethylene-acrylic, polystyrene, and styrene-based softeners.
Easily heat-meltable substances such as butadiene copolymers, rubbers, cellulose derivatives, butyral, polyvinyl alcohol, polyamides, polycarbonates, polyvinyl chloride, epoxymelamine, polyesters, polyether polyurethanes, and the above oligomeric compounds, or lubricants. Examples include oil.

Fillers that have traditionally been used can be used, including metal powders such as silver, copper, iron, and aluminum, metal oxide powders such as alumina, titanium white, glass, etc., and inorganic salt powders such as calcium carbonate and sodium sulfate. , clay, etc. can be cited as specific examples.

〔Example〕

EXAMPLES The present invention will be specifically described below with reference to Examples.

Example 1 Paraffin wax #155 (softening point 69°C) 100 parts by weight and 10 parts by weight of carbon black MA-8, 20
A black hot melt ink was prepared by melting, mixing and dispersing at 0°C.

This ink was hot-melt coated to a thickness of 4F on a heated polyester film with a thickness of 6〃 (comparison material). Stack 5 of these ink sheets alternately on the front and back sides,
4 between two glass plates and under a weight of 5003
It was heated in a constant temperature bath at 5°C.

On the other hand, as an ink sheet of the present invention, polydimethylsiloxane PS 04 manufactured by Chisso Corporation is used on the back side of the ink sheet.
A 1% toluene solution of 3 (n = 370) was applied and air-dried. The coating thickness is 0.2. g (product of the present invention)
. Five ink sheets of the present invention were stacked alternately on the front and back in the same manner as above, sandwiched between two glass plates, and heated in a constant temperature bath at 45° C. under a weight of 500 g at the same time as the above comparative material. When both materials were taken out after heating for 24 hours, blocking occurred in the comparison material, and when an attempt was made to peel it off, ink was randomly transferred to the back surface.

-6 No deterioration was observed in the ink sheet having the polydimethylsiloxane layer of the present invention on the back surface even when it was peeled off.

Example 2゜ Oxidized wax N'p 5-9125 (softening point 63℃
) 100 parts by weight and β-naphthol azo pigment P e
rmanent Carmine F B B O
A magenta hot melt ink was prepared by melting and mixing and dispersing 2.7 parts by weight at 100°C.

4. Apply this ink on a polyester film with a thickness of 6/II under heating. Comparative data for hot melt coating with a thickness of P). As in Example 1, 5 sheets of this ink sheet were stacked alternately on the front and back sides, sandwiched between two glass plates, and
The sample was heated in a constant temperature bath at 45° C. under a weight of 0.09 mm. −
6. As an ink sheet of the present invention, Chisso Corporation type polydimethylsiloxane PS 04 is applied to the back side of the above-mentioned -r ink sheet.
A 1% toluene solution of 9 (n = 3500) was applied and air-dried. The coating thickness is 0.2. It was L4. Five ink sheets of the present invention are stacked alternately on the front and back sides in the same manner as above,
It was sandwiched between two glass plates and heated in a constant temperature bath at 45° C. at the same time as the above comparative material under a weight load of 500 c). 2
When both materials were taken out after heating for 4 hours, blocking occurred in the comparison material, and when attempts were made to peel it off, ink was randomly transferred to the back surface. -6 No deterioration was observed in the ink sheet having the polydimethylsiloxane layer of the present invention on the back surface even when it was peeled off.

〔effect〕

As can be seen from the above examples, the ink sheet of the present invention exhibits extremely excellent blocking resistance.

(that's all)

Claims (5)

[Claims] (1) On the side where the amount of heat is applied, there is the following general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (however, n in the formula is 50
A thermal transfer recording ink sheet comprising a layer made of polydimersiloxane represented by -6000). (2) The thickness of the layer made of polydimer siloxane is 0.
．． The thermal transfer recording ink sheet according to claim 1, which has a particle size of 05-1μ. (3) The thermal transfer recording ink sheet according to claim 1 or 2, wherein the ink sheet is of a melt transfer type. (4) The claim that the melt transfer type ink sheet is prepared from a paraffin wax or ester wax having a melting point of 60-100°C and a coloring material on a 2-12μ polyester film base material. The thermal transfer recording ink sheet according to item 3. (5) Claims 1 to 4, wherein the coloring material contained in the ink sheet is a yellow coloring material having a chlorphenylazo group, a magenta coloring material having a naphtholazo group, or a cyan coloring material having a phthalocyanine structure. The thermal transfer recording ink sheet according to any one of the above.